Latch with dead locking mechanism



Oct. 20, 1953 F. J. RUSSELL ET AL 2,

LATCH WITH DEAD LOCKING MI'ECI'IAIIISM Filed Jan. 28, 1950 4 Sheetg-Sheet l w L Mm FRED J. RUSSELL, RA YMOND W. DIE TRICH GEORGE E, SOLOI/IE'F' INVENTORS.

I-IUEBNER, BE E [17.5 R, WOPRE'L,

HERZ/G J CALDWELL;

ATTORNEYS- Oct. 20, 1953 F. .1. RUSSELL ET AL LATCH WITH DEAD LOCKING MECHANISM Filed Jan. 28, 1950 4 Sheets-Sheet 2 12 a if 29 FRED J. RUSSELL, RAYMOND W. DIE T RICH, 8 a

GEORGE E. SOL OWE FF, INVE N TORS- HUEBNER, BE E HLE R, WORREL, HERZ/G 8 CALDWELL, By A TTOPNEVS.

Oct. 20, 1953 F. J. RUSSELL ET AL LATCH WITH DEAD LOCKING MECHANISM 4 Sheets-Sheet 5 Filed Jan. 28, 1950 w x M J. W F

a m ME TV E0 IL 00 ms a we mm ma 0 in R 3 W E R we m a m N a w H HERZIG d CALDWELL, By A TTORNEYS.

Oqt. 20, 1953 F. J. RUSSELL ET AL 2,

LATCH WITH DEAD LOCKING MECHANISM Filed Jan. 28, 1950 4 Sheets-Sheet 4 FRED J. RUSSELL, f%l\\g :11 RA mo/vo W. D/ETRICH, a i Qggihflg if GEORGE E. SOLOVIEFF, j; INVENTORS.

HUEB/VE/P, BEE/1'1. ER, WORREL,

HERZ/G a CALDWELL,

ATTORNEYS.

Patented Oct. 20, 1953 UNITED} s'r yer osrsic 2,656,207 LATCH WITH DEAD LOCKING MECHANISM Application January 28, 1950, Serial No. 1405986 4 Claims. 1

The inventionrelates todoor latches with dead locking means, namely, mechanism which will re- :sist inward movement of the latch bolt by pressure against the latch bolt when same is engaged in a strike plate.

A general object of the invention is to provide a latch of the character described which is compact, relatively simple in construction, smooth and positive in operation, yet providing indexing means by which knob mechanisms or equivalent are automatically aligned and retained in proper position in relation to the latch assembly.

A more particular object is to provide a dead locking arm which can "be made by a stamping operatiomand-which is supported for andlimited to, a slight rocking movement in-a fi-Xed plane, the support being a spacer in the latch case, and the dead locking arm being urged into dead locking position by spring pressure directed against the arm below the plane of support.

A further object is to provide in combination a central spring partially encased in a tubular latch bolt member, such member being retractable by a main slide member which is normally urged forward by a pair of separated springs disposed rearwardly in the latch case.

Another object is to provide a novel rod slide mechanism connected with a dead locking bolt, and cooperating with the dead locking arm to lift the latter out of dead locking position when the dead locking bolt is advanced.

An additional object is to provide in combination a latch bolt and tubular bolt member, the latter retaining a central spring, a rod slide mechanism connected with a dead locking bolt, and a dead locking arm cooperating with "the rod slide mechanism.

A still further object is to provide in .a latch assembly of the character described a bridge spacer transverse of the latch case furnishing a hold-down guide to retain the rod slide mechanism in correct operating position.

Another obj eat is to provide in a latch assembly of the character described, a novel main slide member normally urged forward bya pair of compresslon springs acting at its rear'end, the springs being hosted in and positioned by a'pair of channels formed at the rear end of a latch case which houses the various working parts, the main slide member having the function, among-other things, r

of engaging the latch bolt assembly'to retract the same.

These and other objects of the invention will become more apparent from the detailed description which follows and by reference to the accompanying drawings.

in'thedrawings:

Figure .1 is :a horizontal plan :view .of our latch 'assemblyinassociation with a door knobassembly mounted in a door, the latter and a (door jamb being illustrated in sect-ion.

Figure 2 is a view taken on line 2-2 of Figure 1.

Figure 3 is an elevational end view of the .door and face plate as seen in the direction of arrows 3--3 in Figure 2. V

Figure i is a perspective view of the latch assembly shown in Figures 1 and 2 with one of the latch case halves separated from theother.

Figure 5 is a view of the latch assembly as seen in the direction of the arrow .5 in Figure l but with one of the latch caseihalvesremoved to .show theparts.

Figure 16 "is a section taken on the .line .6-6 .of Figure 5 and assuming :the latch case to be .complete.

Figure F1 is .a cross section taken .on the line l-l oflFigure 6.

Figure :8 is a .section taken on "line "ii-"8 of Figure 6.

Figure .9 is :a section similar to Figur 6 but showing only the forward portion of the latch assembly and with the latch boltretracted by the main slide member.

Figure 310 is :a view similar to Figure!) showing the dead locking bolt and dead locking arm acting to block the inward thrust of the latch bolt. This occurs by the dead locking arm dropping down, andthe dead locking arm does the blocking after thelatc'h bolt moves inward about 3%".

Figure 11 is a cross section taken on the line l l--H of'Figure 10.

Figure 12 is a section taken on line 12-42 of Figure 9.

Figure 13 is a perspective view of the latch assembly partially exploded and with one-half of the housing case omitted.

Figure 14 is a perspective view similar to Figure 4 but showing a slide bar to use in plac of a knob and spindle to retract the latch bolt.

Our latch assembly 2-8 is illustrated in'association with a door knob assembly 2| mounted in a door 22 which is in proximity with a door jamb 21; on Which-astrike plate 24iS'fiX8d.

The latch assembly is characterized by a dead locking device embodying novel structural and functional features which will be made apparent as the descriptionproceeds.

The latch assembly comprises .a two part case 25 formed of mating :haives '26 and 21 secured t gether at the throat 28 by self-contained tab and slot combinations and by Spacers as will be referred to subsequently. The case embodies, in

addition to the throat 28, a central housing 29, and a spring channel end 30. The throat guides a latch bolt 3|, the central housing confines and supports most of the latch operating parts to be described, and the spring channel end locates and houses a pair of springs which normally advance a main slide member 36.

The latch bolt 3| is formed with a socket 31 which receives a tubular member 38, the latter being rigidly connected with th bolt by a transverse pin 39 which is staked in. A compression spring d seats within the tubular member 38, bearing at One end against the pin 39. Its other end bears against a spring seat 42 of a dead locking arm 43. The dead locking arm 43 has a clearance hole 44 to loosely receiv the sleeve of a mounting bolt means discussed later. The arm 43 has a fulcrum mounting, at its rear end, the details and purpose of which will appear. Sufiice it to say, at this point, that the dead locking arm is restrained against longitudinal movement by its mounting, and the spring 45 yieldably urges the bolt 3| to its advanced position.

This dead locking arm 43 comprises a mounting plate section 46 formed with a transverse slot ll. The slot 4'! receives the upper reduced part 4'! of a spacer 68, upon the shoulders 49 of which the arm 43 fulcrums, the arm being retained between the shoulders 49 and the adjacent wall of the latch case. Forward of the mounting plate section 46 is a depressed bifurcated element 59 formed with fingers with depressed tips 52. Between the fingers 5! is a diametrically struck tongue 53 formed with a hole 54 which receives a pin 55, the latter being part of the spring seat 42. The location of the spring seat on the tongue 53 of the dead locking arm 43 is offset (as shown) from the fulcrum mounting plane on the shoulders 49, as a result of which there is a constant spring pressure against the dead locking arm tending to depress the forward end thereof. The bifurcated element 50 has transversely extending ears 55 which can enter notches 56 in the main slide member 36, the surfaces of such notches acting as stop elements for downward movement of the fingers 5! under influence of the oiTset spring 46. Ears 55 are raised out of notches 55 by cam surfaces 57 and elevated surfaces 58 of slide 36 when slide 36 is retracted at a time when th dead locking bolt is held in by the strike plate and the latch bolt is advanced (Figure this lifting action taking place before the tubular member has moved rearwardly a sufiicient distance to be obstructed by the fingers 52, as later described.

The dead locking arm performs an important function in controlling the dead locking mechanism as a whole, Generally speaking, when it is depressed, the latch bolt cannot be retracted beyond a limited travel by pressure against its outer end, as might be exerted by an unauthorized person prying or prodding with a blade; and when the dead locking arm is raised, the bolt may be pushed in, as by normal sliding contact of the tapered face of the bolt with the strike plate or may be retracted, as by normal rotation of knobs.

The spacer 48 not only offers the fulcrum support for the dead locking arm, as shown and described, but spaces the two halves 25 and 2'! of the latch case 25. Oppositely extending tabs 60 extend through slots Si in the housing and are staked to assist in securing the two halves together, also contributing to the spacing apart of th two halves of the housing, and centering the working parts supported from it. These parts include, in addition to the dead locking arm, a

pair of compression springs 62, the rear ends of which are mounting on spring retainers "53 which extend forwardly from below center at each side of the spacer 8.

The forward ends of the springs 52 bear against the rear ends 55 of a rod slide member '65. latter is a U-shaped element, the legs ii? of which are in alignment with the fingers 5! of th dead locking arm. The tips 52 of these fingers can ride on the upper surface of the legs 5?. Each leg 67 has a T form, the cross piece as of the T being at the rear end of the leg. The lower end of the cross piece 58 rides on the wall of the latch case. The upper end is formed with a taper and functions as a cam when the slide member is shifted. When it is shifted rea-rwardly (Figure 10), the tips 52 move down under the influence of the spring 68 pressing on the tongue 53 of the dead locking arm. When it is shifted forwardly, the tips 52 ride up on the upper end of the cross piece 58 (Figure 6).

The forward. closed end part of the U-shaped rod slide member is a substantially square plate 30 formed with a circular hole ii through which the tubular member 38 is relatively slidable.

The plate 75 is formed with depending lugs l2 adapted to key into slots i3 of a dead locking bolt 15 and thus make a rigid connection therewith. The dead locking bolt l5 has a sliding fit in an auxiliary housing T5 of the latch case.

The latch bolt 3i and the dead locking bolt 75 are retractable together when the dead locking bolt is in advanced position at the start of the movement, as when the door is in the process of being closed. When the dead locking bolt stands retracted, as by restraint imposed by its contact with the strike plate 24 (Figure 10), and while the latch bolt 3! is extended in engagement with said strike plate the extended latch bolt cannot be pushed in, for reasons which will appear.

The rear end of the tubular member 38 is provided with a stop element 85. The latter has a pair of horizontally extending blocks 5i and a vertical block 82. The horizontal blocks are aligned with the tips 52 of the fingers 5i. li nen the tips ar in depressed position, they interrupt rearward movement or" the blocks 8i and consequently of the latch bolt 3 l. When the tips are in elevated position, the interruption is removed, and the blocks SI can then slide under the tips 52. The vertical block 32 and the blocks 8! coact with the main slide member 36 in a manner later described.

The relative sizes and positions of the tips 52 and the raised portions '58 are such that whenever the latch bolt and dead locking bolt are moved rearwardly in unison, as by pushing or pulling the door closed, the tips 52 are not released by the raised portions 68 until after the blocks 3 have already begun to pass under said tips 52,

thus avoiding the possibility of the tips 52 obstructing the rearward movement of the blocks 8| and related tubular member and latch bolt. However, when the latch bolt is released to extended position in engagement with the strike plate 24 while the dead locking bolt still is retained in inward position by the face of said strike plate, the blocks 8! move forward beyond the reach of tips 52, thus allowing said tips under th influence of spring 45 to depress to the position which subsequently would obstruct the rearward movement of the latch bolt as the result of end pressure or prying pressure being exerted against same while said latch bolt is engaged in extended position within said strike plate.

A bridge aids in spacing the halves of the assent? latch casing, having sconce-1s cs conforming to in plan with its closed end piece 8 forward and its free ineduced :94 engaging the springs 35. The opposite ends oi the spacings t seat a outwardly extending butt tahs 19.3 of :a u-s c-ed spacer til at the rear :oi the datch case are guided by slots dd formed ll'lfl the sides of :spacerl diameter of the springs is greater the width "of till 1563;510: 55 :fi' i'i, the springs 35 are so confined by casehalves 2t and 21 asto always be :in :slidable, sanded engagement with slots 1914i. The springs 53.5 yieldably urge the main slide member forward to its limit of movement, governed as later describ ed. Elihe closed end piece .94 :is :tormed with tabs .93 which 1113 into slots 93" :in the case and late staked to .further secure the case. The main slide member also embodies .ca-m surfaces 5-?! which lift, and sari-aces :58 which retain, cars 55 of dead locking (arm .in elevated position above the inward path of blocks ill of tubular member action. :is accomplished when the main slide member .is netracted and dead locking arm happens to be in :a depressed position, which would block or prevent the continued inward movement of the block-s M. The dimensions and relationship to each other of cam surfaces 5'5 and surfaces andears 55 are such that the tips-52 of dead lock- .ingwarm 4'33 are elevated hetero the cross piece 50 of main slide can draw the member 31 d .i-ts 'eblOCkSe34 to the position where said .bloclts v u-ld be in obstructing contact with said tips 82.

The main slide member has the primary tunetion of retracting the latch bolt .Szl by operation of .knob mechanism .or c uivalent mechanism while actuated against pressure of the springs :35

either by a rotatable hub 3501' by a slide bar 96 attached to .a tab -9,2 in a positionon the outside of the case .25 when a grip handle mechanism is used in place of a knob and accomplishing this while completely removing any obstruction of blocks 8.! by the dead locking .arm 43 in advance ,l of the time when the further inward retraction of said latch bolt by said main slidevmem'ber might otherwise be blocked by said dead locking arm.

The hub 95 is formed with annular bosses .9! which have rotatable bearing support in bearings :98 struck from the case halves 126 and v2.1. square hole '39 extends axially through the hub for reception of a square spindle H19 actuated .by one of the .knobs ill I. "Thehu'b comprises twoannular discs'iii? spaced by a cam 18.3.. This cam has identical ends H35 .engageable with .cam .followers 1'06 in the form of projection struck inwardly from the main slide member .35 and .accommodatcd in the space between the two discs T32 of the hub '95. Rotation of thefhub will cause one of the cam ends N to push its companion 'follower .Lilfi back, thus retracting the main slide member. When the cam 1.03 is in neutral position (Figure 8),, the ends 1.05 are both in contact with the cam projections 1025, and this :engage- 7 .ment limits the .iorward movement of the main her 38, the legs .6] of the :rod slide member 166. :yct clearthe "fingers 51 :of the dead lockin amiss. :end piece engages the :stop element 86 including EthezbliIOkS 8:! thereof of the tubular member 38., and thereby moves the tubularmem- :ber-townetract the-latch bolt when 'thexmain slide member is shifted rearwardly.

The werating parts {are assembled in the case half .21., "and the other half 25 is closed down over them. The throat ."23 provides interlocking means in the :form of :tabs 5H3 which project through slots 1H 4 and can be bent to :assist in holding the two halves together. The throat section 1H2 of eaohicasedsalfyis termed witha'wing H15 havinga ,hole lit for the reception of locating bosses Ill theface plate I alt .andsecured rat .these holes by istak'ing. The :latch assembly and :face plate are mounted in a 'door by wood screws 1| l9.

Knobzassemblies L2!) and 1:21! which include the knobs i501 aresecured on opposite sides of the door by the following means. .A mounting plate 122 has extending from .it hollow threaded posts 523 and :IMwh'ichle-x-tend "through aligned holes 1'25 .intherlatchcase. Thepost I123 also goes through the clearance holedl in the dead locking arm and "the post .124 passes through the area between the side walls of the spacer 94. Machine screws I26 and I211 pass througha mounting plate 128 and (are threaded into the posts I23 and I25. This arrangement enables the latch assembly -to be installed in :doors of d-ifierent thicknesses with- :out any adinstment .in the knob assemblies or latch assembly.

A latching type of :assembly is shown in the drawings. The :knob :assembly I20 or 12 l, or equivalent [members such as (grip handles, will embody mechanisms to lock the outside knob or .member against retracting the latch in the case of a locking type .ilock.

Qpcm'tion Assurrting that the'latch is installed-in a door, as illustrated Figures 1 and 2, and that the .door isopcnatthe beginning of the operation, the latchbolt 3| and'the dead locking bolt 'liiare fully advanced under-the combined influence of spring flii acting directly on the'latch bolt, springs 62 acting on the dead locking bolt, and springs 35 acting .on the-main slide-member 36. The dead locking bolt being extended keeps the tips 52 of fingers 5i above the level of blocks 81. The outward limit of movement of the main slide member, as previously indicated, is determined by engage- :ment of the cam Hi3 reposing in neutral position against the cam projections l ttof the main slide member. The-limit of advance movement of the latch bolt 3i 'is determinedby engagement of the stop element and the blocks 8! with the cross piece 99 :of the main slide member. The outward limit of movement of the dead locking bolt 15 is determinediby-engagement of the square plate i9 01" the rod slide member 68 with the rear face 29 :of the :latch member 3i If the .door is drawn closed, the beveled face of the latch "bolt :3! engaging the strike plate 2 3 will cause the latch bolt to hepushed in against the yielding ipressur'eof the spring it. The same action "will push in the dead locking bolt i5 against the pressure of springs 82 due to the engagement of the rear face or the latch bolt 3i with thesqnare plate 19 of the rod slide member its, such tplate being attached to the dead looking bolt. However, the :dead locking bolts cross nieces 68 hold up the fingers'lil until the blocks :83! :have passed under the tips =52. If the peak of the latch bolt passes the inner edge of the strike plate, the latch bolt will advance into the door jamb recess which, however, is not wide enough to simultaneously afford entrance of the dead locking bolt, and the latter will be held retracted by engagemeit with the strike plate as shown .in Figures 1 and 10.

In the latter position, as shown particularly in Figure 10, the tips 52 of the fingers will be lowered to rest on the depressed surface of the rod slide member 67 being thus disposed under the influence of the spring it asserting pressure against the dead locking arm 43 below its point of support on the spacer 48. In such position the forward ends of the tips 52 are aligned to obstruct the blocks SE of the stop element 3i! at the rear end of the hollow tubular member lit thus affording insufficient inward movement of the latch bolt as the result of longitudinal pressure at the outer end thereof to permit the latch bolt 3! to clear the strike plate 24.

To open the door the main slide member 36 is retracted either by turning one of the knobs H2! of the installation illustrated in Figure 1 or drawing on the bolt plate 95 (shown in Figure 1e) by a grip handle mechanism which would constitute an alternate to a knob lili.

When the main slide member is retracted as, for example, through the agency of a knob I ti turning the square spindle Hlii, which in turn rotates i the hub 35, rotating the cam m3 so that one of its peaks l t5 pushes its companion follower Hit back, the ears 55 of the dead locking arm 43 are elevated by reason of sliding contact with cam surfaces 5?. This action elevates the tips 52 of the fingers 5| to a position above the block 8!, a position maintained by the surfaces 58 sliding under while supporting the cars 55 so that the tubular member 33 to which is pinned the latch bolt 3| is free to be drawn inwardly as the main slide member is retracted, which action is accomplished by engagement of the main slide member cross piece 90 with the member 86. During the retraction of the main slide member, the action of elevating the tips 52 of the fingers 55 to i a position above the blocks 8! is accomplished by the cam surfaces 5'! ahead of the time when the main slide member cross piece 98 will have drawn the member 33 to the position where the further inward movement of the blocks iii of member 8t! otherwise would be obstructed by the ends of fingers 5!.

Having retracted the latch bolt and swung the door so that the latch bolt is clear of the strike plate, release of the door knob (or the slide plate 9%) enables the latch bolt as well the dead locking bolt l5 to advance under spring action to the starting position described. In such position the tips 52 of the fingers 5! are elevated by engagement with the raised surfaces of the cross pieces 58 of the rod slide member 56. This elevated position of the finger tips 52 removes the finger tips from their blocking position so that upon a succeeding closing of the door the dead locking bolt '35 and the latch bolt 3! may move inwardly together.

The central portion and the end piece 96 of the U-shaped main slide substantially fill the latch case from top to bottom and along the sides, their sides being rounded to conform to the rounded contour of the side walls of the case, as shown. This sliding fit in the case, and the dual springs, one on each side of the case, assure a free guided movement of the main slide member.

The rod slide of the dead locking mechanism has twin slide elements, twin springs and a cross piece, itself being U-shaped, and the guide for these side elements furnished by the bridge spacer imparts added stability and accuracy of longitudinal movement of the rod slide member.

The cross piece of the rod slide member provides a slide bearing for the tubular member of the latch bolt mechanism, augmented by the arch of the bridge spacer, and the arcuate notches of the cross piece of the main slide member.

The bifurcated dead locking arm is positive in action and functions with exceptionally slight rocking movement.

The whole device is compact, well balanced and smooth in operation. It is easily installed in a door of any thickness, provides indexing holes for alignment of knobs or equivalent trims, and requires no adjustments.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Thus, as an example, the central spring 60 may enclose the tubular member 38 instead of being housed thereby, although such an alternative would present some complications and is not the preferred arrangement. While the U-shaped rod slide mechanism, the bifurcated dead locking arm, the U-shaped main slide member, and dual springs for the rod slide mechanism and. main slide member are preferred, these parts may take different forms, and at some sacrifice of the advantages offered, may be reduced to single instead of dual functioning elements, and single springs may be employed. Other examples of variation will be obvious to one skilled in the art.

The invention having been herein described, what we claim as new and desire to secure by Letters Patent is:

1. In a dead locking tubular latch comprising a casing having a pair of longitudinally separable mating parts forming a single common chamber of uniform cross-sectional area with end and intermediate spacing partitions extending across the casing, automatic latch bolt actuating compcnents and manually responsive latch bolt actuating components, the combination of a main latch bolt including a slide comprising a pair of spaced elements lying slidably against opposite sides of the casing and a return spring means between the casing and said latch bolt, an auxiliary latch bolt reciprocably mounted in the casing and including a rod slide member comprising a pair of legs lying within said spaced elements, and spring return means between the casing and said auxiliary latch bolt, a locking arm having one end apertured and in a position loosely connected to the casing and comprising a pair of fingers at the opposite end lying one adjacent and operably engageable with each leg, a pair of cars lying one adjacent and operably engageable with each of said spaced elements, a tilting spring between a portion of said arm and the main latch bolt, said fingers having a spring-tilted position in abutting relation with the main latch bolt when the auxiliary latch bolt is depressed and a released relation with the main latch bolt when the auxiliary latch bolt is released.

2. In a dead locking tubular latch comprising a casing having a pair of longitudinally separable mating parts forming a single common chamber of uniform cross-sectional area with end and intermediate spacing partitions extending across the casing, automatic latch bolt actuating components and manually responsive latch bolt actuating components, the combination of a main latch bolt including a slide comprising a pair of spaced elements lying slidably against opposite sides of the casing and a return spring means between the casing and said spaced elements, an auxiliary latch bolt reciprocably mounted in the casing, said auxiliary latch bolt including a rod slide member comprising a pair of legs lying within said spaced elements, and spring return means between the intermediate partition and said legs, a single piece dead locking arm having one end apertured and in a position loosely engaged by the intermediate partition and compris ing a pair of fingers at the opposite end having depressed tips lying one adjacent and operably engageable with each leg, a pair of ears lying one adjacent and operably engageable with each of said spaced elements, a transversely extending centrally disposed tongue and a spring between said tongue and the main latch bolt, said tips having a spring-tilted position in abutting relation to the main latch bolt when the auxiliary latch bolt assembly is depressed and a released relation to the main latch bolt when the auxiliary latch bolt is released.

3. In a dead locking tubular latch comprising a casing having a pair of longitudinally separable mating parts forming a single common chamber of uniform cross-sectional area with end and intermediate spacing partitions extending across the casing, automatic latch bolt actuating components and manually responsive latch bolt actuating components, the combination of a main latch bolt including a slide comprising a pair of spaced elements lying slidably against opposite sides or" the casing and a return spring means between the casing and said latch bolt, an auxiliary latch bolt reciprocably mounted in the casing and including a rod slide member comprising a pair of legs lying within said spaced elements, and spring return means between the casing and said auxiliary latch bolt, a locking arm having one end apertured and in a position loosely connected to the casing and comprising a pair of fingers at the opposite end lying one adjacent and operably eng-ageable with each leg, a pair of ears lying one adjacent and operably engageable with each of said spaced elements, a tilting spring between a portion of said arm and the main latch bolt, said fingers having a spring-tilted position in abutting relation with the main latch bolt when the auxiliary latch bolt is depressed and a released relation with the main latch bolt when the auxiliary latch bolt is released, said latch bolts and the dead locking arms having an operative assembled relation in one mating part and the spacing partitions independent of the other mating part thereby to enable assembly with the mating parts in separated relation.

4. In a dead locking tubular latch comprising a casing having a pair of longitudinally separable mating parts forming a single common chamber of uniform cross-sectional area with end and intermediate spacing partitions extending across the casing, automatic latch bolt actuating components and manually responsive latch bolt actuating components, the combination of a main latch bolt including a slide comprising a pair of spaced elements straddling the actuating components and lying slid-ably against opposite sides of the casing and a return sprin means between the casing and said spaced elements, an auxiliary latch bolt having an initially assembled relation with the main latch bolt and reciprocably mounted in the casing, said auxiliary latch bolt including a rod slide member comprising a pair of legs straddling the automatic actuating component and. lying within said spaced elements, and spring return means between the intermedi ate partition and said legs, a single-piece dead locking arm having one end apertured and in a position loosely engaged by the intermediate partition and comprising a pair of fingers at the opposite end having depressed tips lying one adjacent and operably engageable with each leg, a pair of ears lying one adjacent and operably engageable with each of said spaced elements and a transversely extending centrally disposed tongue, a spring between said tongue and the main latch bolt assembly, said tips having a spring-tilted position in abutting relation with the main latch bolt when the auxiliary latch bolt is depressed and a released relation with the main latch bolt when the auxiliary latch bolt is released, said latch bolts and the dead locking arm having an operative assembled relation in one mating part with the spacing partitions independent of the other mating part thereby to enable assembly with the mating parts in separated relation.

FRED J. RUSSELL.

RAYMOND W. DIE'IRICH.

GEORGE E. SOLOVIEFF.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 22,622 Voight Mar. 20, 1945 1,876,081 Schlage Sept. 6, 1932 2,250,727 Schlage July 29, 1941 2,369,873 Voight Feb. 20, 19%5 2,382,663 Quigley et al. Aug. 14, 1945 2,486,268 Erkkila Oct. 25, 1949 2,497,750 Wardwell Feb. 14, 1950 

